It sounds like an environmentally friendly way to liven up your yard or garden: rubber mulch that’s made from recycled tires. Rubber mulch can be use mostly the same way as any other mulch whether it’s for landscaping, gardening, or children’s playground. Most companies that manufactures rubber mulch labels it as a safe, economical and long-lasting alternative to regular wood mulch. Even my neighbor was trying to get me to buy into the whole rubber mulch idea as I spoke to him the last week. But is it really environmentally friendly as many companies claim it to be.
According to a study by Linda Chalker-Scott, Ph.D. an Extension Horticulturist and Associate Professor at Washington State University states that.
Rubber mulches are touted by manufacturers and distributors as permanent (“doesn’t decay away”) and aesthetically pleasing (“no odor” – “looks like shredded wood mulch” – “earth tones and designer colors” – “special fade resistant coating”) landscape materials. Furthermore, we are told that rubber mulch is “safe for flowers, plants and pets” (though it “doesn’t feed or house insects”) and “dramatically improves landscaping.” It seems to be an environmentally-friendly solution to a major waste disposal problem.”
That’s the myth of rubber mulch if you choose to believe the myth of the matter; it isn’t as safe as you might think. Linda Chalker-Scott, Ph. D. further states, “Rubber mulches have not proved to be particularly good choices for either horticultural production or landscape uses. In comparison studies of several mulch types, rubber tire mulch was less effective in controlling weeds in herbaceous perennial plots than wood chips. Similarly, sawdust made better mulch for Christmas tree production in terms of weed control, microbial biomass, and soil chemistry. Another comparative study found rubber to be less effective than straw or fiber mulch in establishing turf grasses.
If you think rubber mulch is still safe to use compare to the other organic mulches, grounded rubber is more likely to ignite and more difficult to extinguish. So in areas where natural or man-made fires are likely to happen rubber mulch should not be used.
Mulching Options
Rubber:
Pros: Uses recycled tires and saves trees, can be dyed to match landscaping, long lasting.
Cons: Cost higher than wood mulch; adds little nutritional value to plants and can add harmful zinc to plants.
Wood:
Pros: Depending on blend, can add a lot higher nutritional value than rubber or rock mulch; good value for the money.
Cons: Has to be laid at least once a year due to decomposition.
Rock:
Pros: Best used for desert type plants.
Cons: Offers no nutritional value; Must prepare to install rocks by first using a layer of weed mat that will act as a mulch agent.
According to one USDA researcher who has studied zinc and other metals in soils and plant materials for decades strongly believes that ground rubber should not be used “in any composting, or in any potting medium, or casually dispersed on agricultural or garden soils” because of zinc toxicity. Studies have shown that rubber leachates are a very complex and can be damaging to humans either in short-term or long-term exposure in high enough concentrations.
Linda Chalker-Scott, Ph.D. basically had this to say about rubber mulch.
Rubbermulch is not as effective as other organic mulch choices in controlling weeds
Rubbermulch is highly flammable and difficult to extinguish once it is burning
Rubbermulch is not permanent; like other organic substances, it decomposes
Rubbermulch is not non-toxic; it contains a number of metal and organic contaminants with known environmental and/or human effects.Source: http://www.puyallup.wsu.edu/~Linda%20ChalkerScott/Horticultural%20Myths_files/Myths/Rubber%20mulch.pdf. “The Myth of Rubberized Landscapes” Linda Chalker-Scott, Ph.D
